The weather forecast that Friday was for rain with a chance of thunderstorms. Luckily, the worst of it came and went early in the afternoon, before most people arrived for Shavuot on the Mountain, a weekend of camping, praying, learning and community-building high in the Oakland hills.

The May 25-27 event in Anthony Chabot Regional Park was organized by Wilderness Torah, a Bay Area nonprofit focused on re-establishing the connection between Judaism and the environment with guided outdoor experiences.

In addition to Shavuot on the Mountain, Wilderness Torah organizes Passover in the Desert and Sukkot on the Farm. The 5-year-old agency also leads b’nai mitzvah programs for youth, as well as other nature-based rituals and holiday celebrations.

“The sages tell us that we hear God’s voice most clearly in the wilderness,” said one of this year’s Shavuot on the Mountain participants, Rachel Rosenberg, 26. The San Francisco resident read the weekly parashah, or Torah portion, during the Saturday morning service.

“This notion is all the more apparent when we have a Torah service outside, a grove of trees as our shelter and a fallen twig as a yad,” she added. A yad is the pointer used to keep one’s place in the Torah scroll.

Reading Torah outside, as she did on Shabbat in the Oakland hills, is “a very powerful experience,” she said. “I felt deeply connected to all of the ancestors who have come before us, who have received revelation and communally wrestled with our tradition.”

This was the fourth year for Shavuot on the Mountain, which used to take place on Mount Tamalpais in Marin until the number of participants outgrew the campsite.

This year’s event started on Friday afternoon and lasted through Sunday, though most of the 175 participants didn’t arrive until Saturday evening’s opening ceremony for Tikkun Leil Shavuot, the all-night text study that is at the heart of the holiday that celebrates God’s giving of the Torah to the Jewish people.

By 6 p.m. Friday the skies were clear, and REI and North Face tents of varying colors and sizes dotted the tree line at the Bort Meadow campground. As people arrived, they registered at “The Oasis,” a makeshift information desk consisting of a foldout table, a couple of camping chairs and a tarp for the roof.

After signing up for a two-hour shift of kitchen duty (everyone does his or her part at Wilderness Torah events), attendees received a small wooden disc and a string. With a Sharpie pen, they made their own nametags.

The participants varied in age and background, and while most live in the Bay Area, some came from as far as New York.

The families who arrived in full formation sported the best camping gear, with huge tents, coolers and inflatable mattresses. The younger crowd — couples and singles, gay and straight — bonded quickly over music, playing their guitars and drums together within moments of meeting each other.

Outside of the ceremonies and the occasional shofar blast, there was little to identify the crowd as Jewish. With knitted beanies and ponchos, as opposed to yarmulkes and tallits, the assembled looked more like a gathering of hippies than a shul on a mountain.

In many ways, Wilderness Torah could be described as Judaism meets New Age, matzah meets crunchy granola. But that’s just the reductive pitch. There’s no denying that Wilderness Torah achieved something so idyllic with Shavuot on the Mountain, at times you had to pinch yourself to confirm that what you saw there was real.

On Friday evening, more than 30 participants welcomed Shabbat on a clear patch of ground furnished with large rugs and pillows under a cluster of redwoods. The service started with acoustic guitars and drums accompanied by singing and dancing.

Rebecca Elswit and Neshama Redstone chopping vegetables

The prayerbook — photocopies in a plastic folder — included Hebrew prayers with translations, alongside songs by Bob Marley, Leonard Cohen and George Harrison. When someone busted out a hula hoop during the service, no one so much as raised an eyebrow.

After that, things slowed down to a more traditional pace and the rituals became more familiar. All present were invited to step up and light a candle as the final rays of sunshine disappeared beyond the horizon.

The young children who didn’t have the patience to sit through the service played with balls and Frisbees, running around in a nearby field.

Every now and then the sound of a jet overhead broke the spell, punctuating the evening’s many powerful moments.

Zelig Golden, 38, the founding co-director of Wilderness Torah, says Judaism and the environment are inseparable because of the ancient traditions that bind Jews to the land and its fruits, and also because of the trouble both Judaism and the Earth face today.

“Environmentally we’re approaching what some would call a challenge, others a disaster,” said Golden, who used to work as an environmental lawyer for the Center for Food Safety in San Francisco. “The same is true for Judaism. Only 1.5 percent of the [U.S.] population is Jewish, and many that make up that number have a hard time connecting with the Jewish customs presented to them.”

Golden rejected Judaism in early life, then found his path back through a nonreligious meditation group that in time led him to Chochmat HaLev’s Jewish Renewal community in Berkeley. That’s where he met Julie Wolk, 35, the other founding co-director of Wilderness Torah, who also couldn’t relate to the traditions she was raised on.

For Sukkot 2007, Golden, Wolk and a handful of other members of Chochmat HaLev organized a camping trip to Sacramento Valley’s Eatwell Farm, their community supported agriculture (CSA) affiliate.

Only a few dozen friends attended that first Sukkot on the Farm; 250 people showed up for last year’s celebration. Today hundreds of people take part in the group’s festivals and ongoing programs.

The Jewish Wilderness Quest, featuring three days and nights of solitude and fasting in Death Valley, is undoubtedly the group’s most challenging ritual experience. (The next one takes place in October.) But Passover in the Desert, a five-day journey to Panamint Valley near Death Valley National Park, is also not for the faint-hearted, although 130 showed up this spring.

Chef Baruch Schwadron in the makeshift kitchen

Devorah Herman of Marin wanted to go, but admitted it was too much of a commitment for her. “Shavuot on the Mountain is a little bit more manageable,” she said.

Saturday evening, Golden stood in the meadow and blew his shofar, heralding the commencement of the Shavuot holiday.

“All our prophets had their epiphanies in nature,” Golden told the crowd of 175 assembled in a huge circle, explaining that if they wished to receive their own revelation they must venture into the wilderness, as well. “Revelation is not a lightning bolt that fills your head with wisdom all at once. It’s when you look at a blade of grass and say, ‘That’s amazing.’ When you see the specks of green in someone’s eyes.”

After music and dancing, the crowd was invited to grab at the ends of the colorful ribbons that hung from the “Omer Pole” and wrap them around it, 49 ribbons in total representing the days between the Exodus from Egypt and the giving of the Torah at Mount Sinai.

A popular adage among attendees was that Wilderness Torah is the Jewish Burning Man: Both festivals aim at establishing a village community — a tribe — in nature.

The comradeship began days prior to the event with an online spreadsheet, where people posted their contact information and arranged carpools for the windy, 15-minute drive from Highway 13 up Redwood Road.

At the campground, an outdoor kitchen was set up. It was managed by a small, dedicated staff, but its operation depended upon the work-exchange attendees and everyone else who put in their two hours.

Blessing the challah

“They’re the heart of this community,” Golden said of the cooking crew, even if the vegetables that slowly cooked overnight in one of the fire pits unfortunately mixed in with some inedible weeds and “didn’t turn out that great,” as Wolk reluctantly admitted.

Strong connections were made during the chores, as people chopped vegetables and washed dishes in tubs — two sets, of course, to keep kosher.

Scott Fischer, 31, of Fairfax, said he enjoyed the weekend. “I was touched by the depth of the community and how open people are with each other,” he said. “There seemed to always be fascinating conversation taking place all around me. I particularly enjoyed the Shabbat service. It’s a stark contrast to the formal benches I am used to sitting in.”

Wilderness Torah makes a concerted effort to accommodate families.

The many kids who populated the “Children’s Village,” a kind of day care where they were entertained and educated while their parents attended other activities, seemed to have as much fun as the adults. Even if they didn’t internalize the messages in the various ceremonies, they still seemed to enjoy playing outdoors for a whole weekend — not an Angry Bird in sight.

Wolk and Golden said that this intergenerational aspect is as integral to Wilderness Torah as is the connection to the environment. During two of the services, Sarai Shapiro, Wilderness Torah’s program coordinator, held hands with the children and made a point of addressing them as those “who will carry on our traditions.”

Reaching for the divine

However, the kids were sound asleep during the nightlong marathon of classes and activities, the “tikkun” that followed the opening Shavuot celebration.

At 10 p.m. Golden led a small group discussion about Shavuot as it’s mentioned in the Torah and secondary texts.

It was very cold and windy, and the pages blew in the wind as people read by flashlight. And yet, all 10 participants huddled in the small circle were thoroughly engaged in the conversation, offering a wide range of perspectives, from mystical to Christian to the zodiac.

Toward the end of the session, Golden explained how he negotiated the contradiction between the written Torah, and his own personal torah, the set of beliefs that guide him through life.

“The Torah is a mirror, and the stories it contains help us see into our deepest truths,” Zelig said. “Whether we read a story that inspires us or a story that disturbs us, the Torah can guide us to refine our personal values and understand how we want to best walk in the world.”

The long night of Tikkun Leil Shavuot was filled with discussions and activities, including some with the eye-catching titles of “Come Not Near a Woman: Gender, Gender Segregation, Purity, and Revelation,” “A Queer’s Eye View of the Scene at Sinai” and “Expanding Identity to Embody Unity: The Art of Remembering (How to make Love to G-d).”

Not far away from Golden’s circle was Rabbi Daniel Lev leading a workshop called “Shema Between the Sheets: Spiritual Intimacy at Bedtime.”

Just a handful of attendees were up for the fireside “Midnight Ritual,” and even fewer made it to the 5 a.m. Shacharit service. By 8 a.m. most people were asleep in their tents, a few brave souls under the open skies. Even Golden and Wolk weren’t in sight, perhaps finally allowing themselves a few hours of sleep.

The two were very pleased with this year’s Shavuot on the Mountain, and expect only better for Wilderness Torah’s future.

“What’s really exciting is that we’re being approached from people all over,” Golden said. “We get requests from Australia, the U.K., Canada, Israel. We want to take what we’re doing here and spread it across the Jewish world.”